印刷ループ数

1828 ワード

public class LoopPrinter {

	/**
	 *  
	 * 
	 * @param row
	 *             
	 * @param col
	 *             
	 * @return
	 */
	public static int[][] loopArray(final int row, final int col) {
		int[][] array = new int[row][col];
		int maxCount = row * col;
		int count = 1;
		int less = row < col ? row : col;
		int loopLimit = less / 2; //  
		if (less % 2 > 0) {
			if (row == col) {
				array[loopLimit][loopLimit] = maxCount;
			}
			loopLimit++;
		}

		for (int loop = 1, i = 0, j = 0; loop <= loopLimit; loop++, i++, j++) {
			for (; j < col - loop; j++) {
				array[i][j] = count++;
			}
			for (; i < row - loop; i++) {
				array[i][j] = count++;
			}
			for (; j > loop - 1 && count <= maxCount; j--) {
				array[i][j] = count++;
			}
			for (; i > loop - 1 && count <= maxCount; i--) {
				array[i][j] = count++;
			}
		}

		return array;
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		int row = 6;
		int col = 5;
		long nano = System.nanoTime();
		int[][] array = loopArray(row, col);
		System.out.println(" :" + (System.nanoTime() - nano) + " ns");

		for (int i = 0; i < array.length; i++) {
			for (int j = 0; j < array[i].length; j++) {
				System.out.print(array[i][j] + "\t");
			}
			System.out.println();
		}
	}

}

 :
int row=6, col=5;
1	2	3	4	5	
18	19	20	21	6	
17	28	29	22	7	
16	27	30	23	8	
15	26	25	24	9	
14	13	12	11	10